Enclose small seashells in clear glass jars with lids. Organize a large collection of shells by color, type, size or where they're from. For example, put shells from different beaches in separate jars. Use jars that are all one size or varied sizes. For example, place large, wide jars in the middle of the shelves and shorter jars on each end of the shelves above or below eye-level to reserve the center shelf for the most attractive shells.
Place colorful, large shells in a standing position to show their most colorful, inside surface on shelves at or near eye-level. For example, line up large shells along the back of the shelves so they lean against the wall with their undersides exposed to the viewer.
Place a large seashell such as a conch shell in the middle of one wall shelf. Arrange medium-sized shells on each side of the large shell. Line the medium shells up in a row, or arrange them in small groups. Place a flat shell or abalone shell full of small shells at each end of the shelf.
Display a group of similar shells on each wall shelf. Add starfish and shells in contrasting colors to add interest. Arrange flat shells such as sand dollars between groups of shells near the edge of the shelf, or display them as a group in a small bowl or large wine glass.
Center a small tabletop fountain on a strong wall shelf in reach of an electrical outlet. Group colorful seashells in the fountain so the water brings out their colors.